
using System;

namespace ConsoleApplication
{
    public class BoilWater {

        public static void Execute() {
            Heater heater = new Heater();
            Heater.Alarm alarm = new Heater.Alarm();

            heater.Boiled += new Heater.BoiledEventHandler(alarm.MakeAlert);    //也可以这么注册
            heater.Boiled += alarm.MakeAlert;    //注册方法
            heater.Boiled += (new Heater.Alarm()).MakeAlert;   //给匿名对象注册方法
            heater.Boiled += Heater.Display.ShowMsg;       //注册静态方法

            heater.BoilWater();   //烧水，会自动调用注册过对象的方法
        }

        class Heater {
            public string type = "RealFire 001";       // 添加型号作为演示
            public string area = "China Xian";         // 添加产地作为演示
            private int temperature;
            //声明委托
            public delegate void BoiledEventHandler(Object sender, BoiledEventArgs e);
            public event BoiledEventHandler Boiled; //声明事件

            // 定义BoiledEventArgs类，传递给Observer所感兴趣的信息
            public class BoiledEventArgs : EventArgs {
                public readonly int temperature;
                public BoiledEventArgs(int temperature) {
                    this.temperature = temperature;
                }
            }

            // 可以供继承自 Heater 的类重写，以便继承类拒绝其他对象对它的监视
            protected virtual void OnBoiled(BoiledEventArgs e) {
                if (Boiled != null) { // 如果有对象注册
                    Boiled(this, e);  // 调用所有注册对象的方法
                }
            }
            
            // 烧水
            public void BoilWater() {
                for (int i = 0; i <= 100; i++) {
                    temperature = i;

                    if (temperature > 99) {
                        if (Boiled != null) { //如果有对象注册
                            // BoilEvent(temperature);  //调用所有注册对象的方法

                            //建立BoiledEventArgs 对象。
                            BoiledEventArgs e = new BoiledEventArgs(temperature);
                            OnBoiled(e);  // 调用 OnBolied方法
                        }
                    }
                }
            }

            // 警报器
            public class Alarm {
                public void MakeAlert(Object sender, Heater.BoiledEventArgs e) {
                    Heater heater = (Heater)sender;     //这里是不是很熟悉呢？
                    //访问 sender 中的公共字段
                    Console.WriteLine("Alarm：{0} - {1}: ", heater.area, heater.type);
                    Console.WriteLine("Alarm: 嘀嘀嘀，水已经 {0} 度了：", e.temperature);
                    Console.WriteLine();
                }
            }

            // 显示器
            public class Display {
                public static void ShowMsg(Object sender, Heater.BoiledEventArgs e) {   //静态方法
                    Heater heater = (Heater)sender;
                    Console.WriteLine("Display：{0} - {1}: ", heater.area, heater.type);
                    Console.WriteLine("Display：水快烧开了，当前温度：{0}度。", e.temperature);
                    Console.WriteLine();
                }
            }
        }
    }
}
